Mila Kunis & Ashton Kutcher Share Passionate Kiss in New York

By Maggie Coughlan

09/19/2012 at 03:25 PM EDT

A Hollywood couple sitting near a tree ... K-I-S-S-I-N-G!

Mila Kunis and Ashton Kutcher were spotted smooching in New York's Central Park on Monday.

With Kutcher, 34, wearing a baseball hat and Kunis, 29, dressed casually in sweats, the famous pair could easily be mistaken for lovestruck tourists visiting the park.

"They held hands and were very affectionate," an onlooker tells PEOPLE. "They seemed to enjoy exploring the city together. They looked very relaxed and seemed very happy together."

PHOTOS: Ashton & Mila's N.Y.C. PDA in 5 Clicks

The couple – who was first linked in April – shared a romantic summer that included vacationing in Bali and attending a baseball game in L.A.

The relationship comes 14 years after Kutcher and Kunis first met filming That '70s Show.